EP0275847A1

EP0275847A1 - Cross-country ski binding and ski boot therefor

Info

Publication number: EP0275847A1
Application number: EP87850318A
Authority: EP
Inventors: Thomas Wassberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-10-30
Filing date: 1987-10-22
Publication date: 1988-07-27
Also published as: NO864346L; NO864346D0; NO160686B; NO160686C; FI874711A; FI874711A0

Abstract

An arrangement in a ski binding for fastening a ski boot with a front sole extension (7) which shows less width than the remaining sole, comprising a toe iron (1) with an approximately plane mounting plate (2) having a portion (2′) which is intended as a support of the sole extension (7), and a portion (2ʺ) directed rearwards and intended as a support of the front portion of the wider part of the sole. The plate (2) intended as a support of the front portion of the wider part of the sole, has less width than the cooperating sole, and that at the edges of said portion of the mounting plate there are bent-up lateral edges (9,10) of less height than the thickness of the sole and intended for cooperation with grooves (23,24) in the underside of the sole.

Description

The present invention mainly concerns an arrangement in a ski binding for fastening a skiing boot provided with a front sole extension which has a smaller width than the remaining sole, comprising a toe iron with an approximately plane mounting plate and a portion intended to support the sole extension, and a portion facing to the rear and intended to support the front portion of the wider sole portion, and with the front portion of said toe iron being provided with a means for holding the toe extension, and with the portion of said mounting plate serving as a support of the sole extension being provided with lateral portions that are bent up to serve as lateral supports of the sole extension. The invention also relates to a skiing boot intended for use in connection with said ski binding.
In ski bindings of the above kind only the sole extension facing forward is fastened to the ski. Any bending of the boot sole, thus, occurs in the forward area of the boot sole, in the last phase of kick off bending occurs quite in front, at or even in front of the toe area of the foot. The object of such a binding is that the skier should achieve maximum length of step in kicking off. Utilization of such bindings is rendered possible by the very carefully prepared trails we find almost everywhere to day.
Obviously, the ski boot receives hardly any lateral control by such a binding. This has a negative effect in case of downhill running when a lateral force will act on the boot when the skier turns, said force urging the boot out relative to the ski. With the extremely light-weight boots used today this is a considerable disadvantage. Also when the skier goes upphill and has to put the skis at a certain angle relative to the trail direction (herring-bone) there will be lateral forces acting on the boot.
In order to remedy this disadvantage it is known to provide guide cam means both at the sole and at the heel for cooperation with grooves in the boot sole or boot heel. Such guide cam means with cooperating grooves were arranged in the central portion of the boot and extend approximately in parallel with the longitudinal direction of the ski.
When the new skiing technique with skating is used other forces will occur between boot and ski. In kicking off, especially during the last phase of kicking off the skier's foot will direct a force forming a certain angle with the vertical line on the ski surface. This means that the skier tends to lift the outer side of the boot from the ski, which is due to the fact that the ski is laterally inklined in connection with skating. causing the contact between ski and snow support occurs essentially on the lower half of the ski. Centrally provided guide means will, thus, not have much effect, since the boot sole is mainly in contact with the lower edge of the ski.
Another disadvantage of the above mentioned bindings is that they have a very restricted extension in the longitudinal direction and, thus, essentially only support the sole extension and, possibly, the foremost portion of the wider sole portion.
With the extremely narrow skis used to day a skier having a relatively wide foot will, thus, have insufficient support for the widest portion of the foot, i.e. ball of the foot, which is the portion of the foot to receive most contact pressure against the ski and, thus, the heaviest load. For skiers kicking off strongly when skating the thin sole of a modern ski boot will bend in the longitudinal direction of the sole, and this may cause a painful load. Some skiers had to reinforce the sole by the aid of a material with high bending strength.
It is an object of the present invention to eliminate the above mentioned disadvantages and to propose an arrangement in a ski binding of the kind mentioned above to achieve good lateral guidance when skating steps are used and, furthermore, an improved support of the wider portion of the skiing boot at the ball of the skiers foot. It is also an object of the invention to propose a skiing boot for use in connection with such a ski binding.
According to the invention this is achieved by the aid of a ski binding of the kind mentioned above which is characterized by the fact that the portion of the mounting plate that is intended for supporting the front portion of the wider part of the sole has a smaller width than that of the cooperating sole, and that the edges of said portion of the mounting plate are provided with bent up lateral edges with a smaller height than the thickness of the sole and intended for cooperation with grooves in the underside of the sole.
A preferred embodiment of the invention is characterized by the fact that each of the two lateral edges of the mounting plate follows a straight line, so that the bent-up lateral portions for supporting the edges of the sole extension form a straight extension of the bent-up lateral portions at the portion of the mounting plate that is extended rearwards. Further features of the binding will appear from dependent claims 3 and 4.
An arrangement in a skiing boot with a front sole extension which has a smaller width than the remaining sole, for use in connection with a ski binding og the kind mentioned above is characterized by the fact that the sole extension turns into a wider portion of the sole via steps on both sides of the sole, and that a groove is provided in the underside of the wider sole portion, starting from the inner corner of the steps/shoulders and extending rearwards.
The invention will now be disclosed in more detail with reference to the drawings, showing embodiments of the invention.

Figure 1 shows a binding according to the invention,
Figure 2 shows the underside of a boot sole according to the invention, and
Figure 3 shows a variant of the binding according to Figure 1.

Binding 1 in Figure 1 comprises a toe iron 1 with a plane mounting plate 2. Mounting plate 2 is wider at its rear edge than at its front edge, and the lateral edges 3 and 4, thus diverge from the front to the rear. Each of the lateral edges 3 and 4 are provided with bent-up edge portions 5 and 6. The front portion 5′, and 6′, respectively, of said edge portions is intended as a lateral guide for the sole extension 7 of sole 8 of a skiing boot. Said portions 5′, 6′ have the same or greater height than the thickness of extension 7. The rear portions 9 and 10 of the bent-up lateral portions 5 and 6, respectively, have less height than the bent-up portions 5′ and 6′, respectively, and they also have a smaller height h than thickness t of the boot sole (cf. Figure 3). Mounting plate 2 of toe iron 1 is provided with apertures for fastening the toe iron to a ski 12. At the narrow front portion 2′ of the mounting plate which serves to receive and support the sole extension 7 pins 13 projecting upwards are provided to cooperate with and pass through corresponding apertures 14 in the sole extension 7 when in use. At the front portion 2′, furthermore, a fastening means for the boot sole extension 7 is provided. Said fastening means is commonly known and, thus, does not form part of the invention. In Figure 1 it is shown as a simple clamping means comprising a threaded pin 15 which is fastened at the front portion 2′ of mounting plate 2. A plate 16 with an aperture 17 is provided to be fitted onto pin 15 after a skiing boot with its sole extension 7 is inserted into the toe iron, so that pins 13 engage in apertures 14. Sole extension 7 is clamped to plate portion 2′ by the aid of plate 16 and a wing nut 18. In Figure 3 another embodiment of a fastening means is shown. This latter means comprises an angular lever 19 which is rotatable about an axle 20 which is firmly arranged in upwards extended lugs 21 of the lateral edges 5′. In the Figure the binding is shown in a position for use with the boot fastened in the binding, and the locking arm 19′ of lever 19 turned to an over centre position and clamping the boot sole. The pressure from the locking arm may, if desired, be distributed by a pressure plate not shown. Actuating arm 19ʺ of lever 19 is pressed down towards the upper side of ski 12 and forms a sloping face which will prevent snow from collecting inside the binding.
As will appear from Figure 2 the wider portion of the sole turns into the front sole extension 7 via steps 20, 21. From the corner 22, i.e. the transition between steps 20, 21, and the sole extension 7 grooves or channels 23, 24 are provided in the underside of the sole to correspond to the cams or bentup lateral edges 9, 10 of the toe plate. When the skiing boot is mounted grooves 23, 24 will, thus, engage the bent-up portions 9,10 and form an efficient lateral guide. The lateral guide will be efficient both for diagonal gait, i.e. when the ski is moved flat on a ski track, and for skating steps as well. Even if the boot is placed on edge, i.e. inclined relative to the surface of the ski, the boot will be in engagement with the inner cam or the raised portion 9 og 10 will be in inside groove 23 or 24 all the time.
As will appear from Figure 2 the toe iron of the binding provides for good support to the wider portion of the sole, since the toe iron supports most of the surface of said wider portion all the way back to the ball of the foot. Thus, the sole is prevented from sagging towards a narrow ski.

Claims

1. An arrangement in a ski binding for fastening a ski boot with a front sole extension (7) which shows less width than the remaining sole (8), comprising a toe iron (1) with an approximately plane mounting plate (2) having a portion (2′) which is intended as a support of the sole extension, and a portion (2ʺ) directed rearwards and intended as a support of the front portion of the wider part of the sole, and where the front portion of the toe iron is provided with a means (15, 16, 17, 18) for firmly holding the sole extension, and where the portion of the mounting plate serving as a support of the sole extension is provided with bent-up lateral porttions (5,6) serving as lateral supports for the sole extension, characterized in that the portion (2ʺ) of the mounting plate intended as a support of the front portion of the wider part of the sole (8) has less width than the cooperating sole, and that at the edge of said portion (2ʺ) of the mounting plate there are bent-up lateral edges (9, 10) of less height than the thickness of the sole and intended for cooperation with grooves (23, 24) in the underside of the sole.

2. An arrangement as defined in claim 1,
characterized in that each of the two lateral edges (3,4) of the mounting plate follows a straight line, so that the bent-up lateral portions (5′,6′) for supporting the edges of the sole extension form a straight extension of the bent-up lateral portions (9,10) of the portion (2ʺ) of mounting plate (2) that is extended rearwards.

3. An arrangement as defined in claims 1 and 2,
characterized in that the two laterial edges (5,6) of the mounting plate diverge in a rearward direction.

4. An arrangement as defined in claim 1, 2 or 3, characterized in that the bent-up portions (9,10) on the rearward directed part (2ʺ) of the mounting plate have an upwards decreasing cross section.

5. An arrangement in a skiing boot with a front sole extension for use in connection with the ski binding as defined in claims 1-4, characterized in that the sole extension (7) changes into a wider portion (8) of the sole via steps at both sides of the sole, and the in the underside of the wider sole portion grooves are provided from the inner corner of the step og angular apex (22) and rearwards, adapted to the bent-up portions (9,10) of the binding.